This section provides background information related to the present disclosure which is not necessarily prior art.
A subject, such as a human patient, may select or be required to undergo a surgical procedure to correct or augment an anatomy of the patient. The augmentation of the anatomy can include various procedures, such as movement or augmentation of bone, insertion of implantable devices, or other appropriate procedures. A surgeon can perform the procedure on the patient based on images of the patient, which can be acquired using an x-ray scanner having an imaging system. The images may be acquired prior to or during the procedure. The imaging system may be, for example, an O-Arm or C-Arm imaging system. The images may be fluoroscopic or radiographic images depending on an operating mode of the imaging system.
The acquired images of the patient can assist a surgeon in planning and performing the procedure. A surgeon may select a two dimensional image or a three dimensional image representation of the patient. The images can assist the surgeon in performing a procedure with a less invasive technique by allowing the surgeon to view the anatomy of the patient without removing overlying tissue (including dermal and muscular tissue) when performing a procedure.
An O-Arm imaging system includes an ‘O’-shaped gantry and a ‘O’-shaped rotor. A C-Arm imaging system includes a ‘C’-shaped gantry and a ‘C’-shaped rotor. Each of these imaging systems typically includes an x-ray source and a x-ray detector mounted opposite each other on the corresponding rotor. Each of the x-ray sources generates x-rays, which are directed at a subject. Each of the x-ray detectors detects the x-rays subsequent to the x-rays passing through the subject.
Although traditional O-Arm and C-Arm imaging systems were capable of taking 360 degrees of images around a subject, the imaging systems were incapable of rotating the rotors more than 360 degrees (or one full rotation). Thus, the systems were incapable of continuously rotating the rotors in a same direction. Once the rotors were rotated 360 degrees, the rotors were rotated back in an opposite direction to the initial (or 0° position). An imaging system having a rotor that is 360° rotation limited typically includes cables, which are used to (i) provide power to device on the rotor, and/or (ii) transfer communication signals between the devices on and off of the rotor. The cables may extend in the corresponding gantry and may be pulled around the rotor during imaging and retracted to an initial state when the rotor is returned to an initial position.
It is advantageous to provide an imaging system with a continuously rotating rotor such that the rotor is not 360° rotation limited. This is especially true when imaging blood vessels. For this reason, certain imaging systems are available that are capable of continuously rotating a corresponding rotor in a same direction. The imaging systems that are continuous rotor rotation capable include an x-ray source, an x-ray detector, and a generator, which are mounted on the rotor. The generator converts a low-voltage (e.g., 400 volts (V)) to a high-voltage (e.g., 150 kilo-volts (kV)). The high-voltage is provided to the x-ray source. In order to provide power to the generator, slip rings are used to pass, for example, the 400V of power from a stationary power source in the gantry to the generator, which is on the rotor. The slip rings are expensive to purchase and maintain due to the required scheduled maintenance of the slip rings.
As another example and instead of using slip rings, inductive coupling may be used to convert the low-voltage to the high-voltage. This includes placing secondary coils around a rotor of a gantry and a stationary primary coil inductively transferring power from the secondary coils to the primary coil. Power received by the secondary coils is provided to the device (e.g., an x-ray source) on the rotor. This type of imaging system include a large number of coils, is complex, and can require additional energy to rotate the rotor due to the added weight of the secondary coils and corresponding circuitry.